Diamond core drilling equipment is used extensively to drill circular or annular holes in rock, earth, and related materials for a variety of reasons. For example, holes are drilled in rock during mining or during exploration for purposes of determining soil compaction, determining soil percolation or to perform other geological research.
Prior art diamond core drill bits or hole saws of a general type that are commonly used in mining applications have cutting segments of such bits that are commonly attached using infiltration techniques.
Generally speaking, diamond core drilling equipment comprises a motor-driven core drill assembly including a down-hole mining core drill bit or hole saw. The core drill assembly may embody various configurations, but such assembly generally comprises a base and a guide column extending up from the base or a drilling rig. A carriage may be provided between the column and the motor for guiding the motor along the column as the pipe extensions and mining core drill bit are advanced beneath the ground surface. Generally, the core bit is attached to the pipe extensions using a driver or reaming tool.
The prior art provides various types of core drill bits for use in mining. However, the majority of commercial mining bits used today have cutting heads formed of a diamond impregnated (infiltrated) material. More particularly, the cutting head comprises a plurality of cutting segments or teeth mounted at the distal end of the cylindrical body of the bit. Each of the segments normally has a uniform concentration of diamond particles dispersed throughout the segments and is attached to the cylindrical body of the bit using an infiltration process. This attachment process, however, is a time consuming operation, it is costly, and may at times result in inadequate adhesion of the segments with the body especially when the segments are highly loaded with diamond particles. Often, the infiltrated material “drips” onto unintended portions of the body and must be cleaned afterwards or fails to adhere properly to the diamond impregnated cutting segments. A substantial investment of energy and time may be required to clean the tool of the stray brazing material and to properly adhere each cutting segment. Additionally, the uniform dispersion of diamonds in the cutting segments may produce only adequate drilling efficiency.